I made a remote player for the Subsonic Server.
It's a Java program that gets the current playing song via the API for a certain player id.
With this system, you can install multiple players around your house, or make a jukebox without the subsonic jukebox feature, if your server does not support audio.
How to use it?
Download the zip file: http://www.projectv.be/downloads/SubsonicPlayer.zip
Unzip Subsonic Player.zip
open config.properties with a text editor and edit the values as following:
subsonic.userName=your_user (change this to your subsonic userName)
subsonic.password=your_pass (change this to your subsonic password)
subsonic.playerId=1 (to know this, see *)
subsonic.pollingInterval=1000 (this is the interval in milliseconds the player will poll subsonic for the current song. don't change this, unless you know what you're doing)
subsonic.serverUrl=http://localhost:4040 (change this to your subsonic server url)
* how to know the player id ? Open the Subsonic web interface, go to settings, select the player you wish to use (should be a web player) and hover over the 'delete player' or 'clone player' link. In the status bar of your browser you should see something like http://localhost:4040/playerSettings.view?delete=52 or http://localhost:4040/playerSettings.view?clone=52
where 52 is your player id
When finished the editing, save the config.properties en run start.sh (on a Linux or Mac system) or start.bat on a windows system.
Ensure yourself Java is installed and in your path.
Now go into your Subsonic web interface, select the player you configured in the config.properties, mute it, and play a song. The remote player should pick it up.
Note: there is no support for stopping the player yet. You should close the program or play a silent mp3

If you have any questions or trouble, please ask here.